Process of making an abrasive disk



Nov. 17,1931. AHJ. DOERMANN 1,332,535

I PROCESS OF MAKING AN ABRASIVE DISK Filed Dec. 6, 1950 Wig g n! 1 henfz wez'icf aermnn; azzswm. 5*

Patented Nov. 17, 1931 UNIT-ED sTA'ras "PATENT? OFFICE ALBERT J. DOEBMANN, OF CHICAGO, ILLINOIS,'ASSIGNOR T ABRASIV'EB CO.,

INC, 0! CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS PROCESS OF MAKING- AN ABBASIVE DISK Application filed December 6, 1830. Serial 80. 500,626. a

cut holes 11 to aid in the attachment of the This invention relates to improvements in the process of making abrasive disks.

Among the features of my invention is the provision of an abrasive disk mounted upon a metal back. Means are provided for pro tecting the metal back from injury bythe bonding material. It has been found, in connection with wheels as heretofore made, that the metal back may be injuriously alfected by certain bonding materials. For example, some of the best bonding materials, such as magnesium oxochloride, will attack metal. Many of these substances, however, form excellent bonding materials for the abrasive imbedded therein. Their use, therefore, is de sired in connection with the making of a grinding disk if injuries to the metal back can be prevented. The principal feature of my invention is such protection of the'metal back from attack by the principal bonding mateiialkused in the manufacture of the grinding In general, I may state that this protection is accomplished by providing over the metal back a coating of water and heat-resisting cement, for example, bakelite cement. This cement will adhere firmly to the metal back and a layer of other bonding'material, for

example, magnesium oxochloride with abrasive imbedded therein, maybe put over the coating of cement, to which it will adhere.

, The coating of waterand heat-resisting cement will protect the metal back against injury from the magnesium oxochloride bondmg material.

Other features and advantages of my invention will appear more fully as I proceed with my specification.

In that form of device embodying the features of my invention shown is the accompanying drawings- Figure 1 is a view in front elevation with portions of the layers broken away; Fig. 2 is a fragmentary enlarged sectional view; Fig. 3 is a horizontal sectional view; and Fig. 4 is a top plan view.. 3 a

As shown in the drawings, the abrasive or grinding disk or wheel includes the metal ack 10 here shown as providedwith-unden v abrasiye.

In the manufacture of the disk, there is first laid over the metal back 10 a coating 12 of water and'heat-resisting cement, for example, bakelite cement. Some abrasive such as silicon carbide in granular form is pref erably imbedded in this cement.

Over the coating of water and heat-resisting cement 12 there is molded the principal art of the abrasive disk, here shown as a ayer of bonding material with abrasive imbedded therein, as indicated by 13. The bonding material used in this layer may be of that kind that will attack or injure metal,

but such injury is prevented in this case by the coating of water and heat-resisting cement 12 underneath the same. This coating is impervious to most acids and will protect the metal back from the rusting or other injurious effects of magnesium oxochloride and other similar substances.

' I prefer to lace some abrasive material in the coating 0 cement 12 as I have found that this will increase the attachment between this coating and the layer 13. It is to be understood, of course, that if bakelite cement is used for the coating 12, it is hardened or baked in the usual manner.

- It is to be understood, also, that practically any kind'of bonding material may be used in the layer 13 as the coating 12 will protect the metal back 10 from injury. For exam- Ele, the bonding material in the layer 13 may e a magnesium oxochloride cement, silicate of soda cement, and the like. It is also to be understood that other cements may be used in the coating 12 instead of bakelite cement. Any cement that will protect the back 10 against damage from in ury by the bonding material in the layer 13 may be used. For example, the coating 12 may consist of bakelite cement, gilsonite, baking paints, lacquers, varnishes, enamels, and the like. Any substance may be used in the coating 12 that will protect the disk 10 against corrosive action of the magnesium-oxochloride or other material used in the layer 13 maybe employed,

provided that such coating will form a surair While I have shown and described certain embodiments of my invention, it is to be understood that it is capable ofmany modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claim, in which it is my intention to claim all novelty inherent inmy invention as broadly as permissible, in view of the prior art.

What I- regard as new, and desire to secure by Letters Patent, is:

The method of making an abrasive disk bonded with a corrosive cement united to a metallic backing, which consists in first coating the backing with a corrosion-resistant cement containing abrasive particles to which the bond of the disk will adhere, and then molding the abrasive disk upon the coated backing.

In witness whereof, I have hereunto set my hand, this 4th day of December, 1930.

. ALBERT J. DOERMANN. 

